Automated Lane Keeping Co-Pilot For Autonomous Vehicles

ABSTRACT

An automotive vehicle includes a vehicle steering system, an actuator configured to control the steering system, a first controller, and a second controller. The first controller is in communication with the actuator. The first controller is programmed with a primary automated driving system control algorithm and is configured to communicate an actuator control signal based on the primary automated driving system control algorithm. The second controller is in communication with the actuator and with the first controller. The second controller is configured to, in response to a first predicted vehicle path based on the actuator control signal deviating from a current lane, control the actuator to maintain a current actuator setting. The second controller is also configured to, in response to the first predicted vehicle path being within the current lane, control the actuator according to the actuator control signal.

TECHNICAL FIELD

The present disclosure relates to vehicles controlled by automateddriving systems, particularly those configured to automatically controlvehicle steering, acceleration, and braking during a drive cycle withouthuman intervention.

INTRODUCTION

The operation of modern vehicles is becoming more automated, i.e. ableto provide driving control with less and less driver intervention.Vehicle automation has been categorized into numerical levels rangingfrom Zero, corresponding to no automation with full human control, toFive, corresponding to full automation with no human control. Variousautomated driver-assistance systems, such as cruise control, adaptivecruise control, and parking assistance systems correspond to lowerautomation levels, while true “driverless” vehicles correspond to higherautomation levels.

SUMMARY

An automotive vehicle according to the present disclosure includes avehicle steering system, an actuator configured to control the steeringsystem, a first controller, and a second controller. The firstcontroller is in communication with the actuator. The first controlleris programmed with a primary automated driving system control algorithm,and is configured to communicate an actuator control signal based on theprimary automated driving system control algorithm. The secondcontroller is in communication with the actuator and with the firstcontroller. The second controller is configured to, in response to afirst predicted vehicle path based on the actuator control signaldeviating from a current lane, control the actuator to maintain acurrent actuator setting. The second controller is also configured to,in response to the first predicted vehicle path being within the currentlane, control the actuator according to the actuator control signal.

According to at least one embodiment, the second controller is furtherconfigured to, in response to a second predicted vehicle path based onthe current actuator setting deviating from the current lane, controlthe actuator based on a fallback command. In such embodiments, thesecond controller may be configured to predict a first perpendiculardistance between a detected lane marker and the first predicted vehiclepath and to predict a second perpendicular distance between the detectedlane marker and the second predicted vehicle path.

According to at least one embodiment, the second controller isconfigured to predict the first vehicle path based on the actuatorcontrol signal in response to the actuator control signal.

According to at least one embodiment, the first controller is associatedwith a first CPU and the second controller is associated with a secondCPU.

According to at least one embodiment, the vehicle further includes asecond actuator configured to control a vehicle throttle, a thirdactuator configured to control vehicle brakes, and a fourth actuatorconfigured to control vehicle shifting. In such embodiments, thecontroller is additionally in communication with the second actuator,third actuator, and fourth actuator.

A method of controlling a vehicle according to the present disclosureincludes providing the vehicle with an actuator configured to controlvehicle steering, throttle, braking, or shifting. The method alsoincludes providing the vehicle with a first controller in communicationwith the actuator and having a primary automated driving system controlalgorithm. The method additionally includes providing the vehicle with asecond controller in communication with the actuator and the firstcontroller. The method further includes communicating, from the firstcontroller, an actuator control signal based on the primary automateddriving system control algorithm. The method further includes, inresponse to a first predicted vehicle path based on the actuator controlsignal deviating from a current lane, controlling, by the secondcontroller, the actuator to maintain a current actuator setting.

According to at least one embodiment, the method additionally includes,in response to the first predicted vehicle path being within the currentlane, controlling the actuator based on the actuator control signal.

According to at least one embodiment, the method additionally includes,in response to a second predicted vehicle path based on the currentactuator setting deviating from the current lane, controlling theactuator based on a fallback command.

According to at least one embodiment, the method additionally includespredicting, by the second controller, a first perpendicular distancebetween a detected lane marker and the first predicted vehicle path, andpredicting, by the second controller, a second perpendicular distancebetween the detected lane marker and the second predicted vehicle path.

A system for autonomous control of a vehicle according to the presentdisclosure includes an actuator, a first controller, and a secondcontroller. The actuator is configured to control vehicle steering,throttle, braking, or shifting. The first controller is in communicationwith the actuator, and is configured to communicate an actuator controlsignal based on a primary automated driving system control algorithm.The second controller is in communication with the actuator and with thefirst controller. The second controller being configured to, in responseto a first predicted vehicle path based on the actuator control signaldeviating from a current lane, control the actuator to maintain acurrent actuator setting.

According to at least one embodiment, the second controller is furtherconfigured to, in response to a second predicted vehicle path based onthe current actuator setting deviating from the current lane, controlthe actuator based on a fallback command. In such embodiments, thesecond controller may be configured to predict a first perpendiculardistance between a detected lane marker and the first predicted vehiclepath and to predict a second perpendicular distance between the detectedlane marker and the second predicted vehicle path.

According to at least one embodiment, the second controller isconfigured to predict the first vehicle path based on the actuatorcontrol signal in response to the actuator control signal.

According to at least one embodiment, the first controller is associatedwith a first CPU and the second controller is associated with a secondCPU.

According to at least one embodiment, the actuator is configured tocontrol vehicle steering. In such embodiments, the system furtherincludes a second actuator configured to control a vehicle throttle, athird actuator configured to control vehicle brakes, and a fourthactuator configured to control vehicle shifting. In such embodiments,the controller is additionally in communication with the secondactuator, third actuator, and fourth actuator.

Embodiments according to the present disclosure provide a number ofadvantages. For example, embodiments according to the present disclosuremay enable independent validation of autonomous vehicle control commandsto aid in diagnosis of software or hardware conditions in the primarycontrol system. Embodiments according to the present disclosure may thusbe more robust, increasing customer satisfaction.

The above advantage and other advantages and features of the presentdisclosure will be apparent from the following detailed description ofthe preferred embodiments when taken in connection with the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic representation of a vehicle according to thepresent disclosure;

FIG. 2 is a schematic representation of a first embodiment of a systemfor controlling a vehicle according to the present disclosure;

FIG. 3 is a schematic representation of a second embodiment of a systemfor controlling a vehicle according to the present disclosure; and

FIG. 4 is a flowchart representation of a method for controlling avehicle according to the present disclosure.

DETAILED DESCRIPTION

Embodiments of the present disclosure are described herein. It is to beunderstood, however, that the disclosed embodiments are merely examplesand other embodiments can take various and alternative forms. Thefigures are not necessarily to scale; some features could be exaggeratedor minimized to show details of particular components. Therefore,specific structural and functional details disclosed herein are not tobe interpreted as limiting, but merely as a representative basis forteaching one skilled in the art to variously employ the presentinvention. As those of ordinary skill in the art will understand,various features illustrated and described with reference to any one ofthe figures can be combined with features illustrated in one or moreother figures to produce embodiments that are not explicitly illustratedor described. The combinations of features illustrated providerepresentative embodiments for typical applications. Variouscombinations and modifications of the features consistent with theteachings of this disclosure, however, could be desired for particularapplications or implementations.

Referring now to FIG. 1, an automotive vehicle 10 according to thepresent disclosure is shown in schematic form. The automotive vehicle 10includes a propulsion system 12, which may in various embodimentsinclude an internal combustion engine, an electric machine such as atraction motor, and/or a fuel cell propulsion system.

The automotive vehicle 10 also includes a transmission 14 configured totransmit power from the propulsion system 12 to vehicle wheels 16according to selectable speed ratios. According to various embodiments,the transmission 14 may include a step-ratio automatic transmission, acontinuously-variable transmission, or other appropriate transmission.

The automotive vehicle 10 additionally includes a steering system 18.While depicted as including a steering wheel for illustrative purposes,in some embodiments contemplated within the scope of the presentdisclosure, the steering system 18 may not include a steering wheel.

The automotive vehicle 10 additionally includes a plurality of vehiclewheels 16 and associated wheel brakes 20 configured to provide brakingtorque to the vehicle wheels 16. The wheel brakes 20 may, in variousembodiments, include friction brakes, a regenerative braking system suchas an electric machine, and/or other appropriate braking systems.

The propulsion system 12, transmission 14, steering system 18, and wheelbrakes 20 are in communication with or under the control of at least onecontroller 22. While depicted as a single unit for illustrativepurposes, the controller 22 may additionally include one or more othercontrollers, collectively referred to as a “controller.” The controller22 may include a microprocessor or central processing unit (CPU) incommunication with various types of computer readable storage devices ormedia. Computer readable storage devices or media may include volatileand nonvolatile storage in read-only memory (ROM), random-access memory(RAM), and keep-alive memory (KAM), for example. KAM is a persistent ornon-volatile memory that may be used to store various operatingvariables while the CPU is powered down. Computer-readable storagedevices or media may be implemented using any of a number of knownmemory devices such as PROMs (programmable read-only memory), EPROMs(electrically PROM), EEPROMs (electrically erasable PROM), flash memory,or any other electric, magnetic, optical, or combination memory devicescapable of storing data, some of which represent executableinstructions, used by the controller 22 in controlling the vehicle.

The controller 22 is provided with an automated driving system (ADS) 24for automatically controlling various actuators in the vehicle 10. In anexemplary embodiment, the ADS 24 is configured to control the propulsionsystem 12, transmission 14, steering system 18, and wheel brakes 20 tocontrol vehicle acceleration, steering, and braking, respectively,without human intervention.

The ADS 24 is configured to control the propulsion system 12,transmission 14, steering system 18, and wheel brakes 20 in response toinputs from a plurality of sensors 26, which may include GPS, RADAR,LIDAR, optical cameras, thermal cameras, ultrasonic sensors, and/oradditional sensors as appropriate.

The vehicle 10 additionally includes a wireless communications system 28configured to wirelessly communicate with other vehicles (“V2V”) and/orinfrastructure (“V2I”). In an exemplary embodiment, the wirelesscommunication system 28 is configured to communicate via a dedicatedshort-range communications (DSRC) channel. DSRC channels refer toone-way or two-way short-range to medium-range wireless communicationchannels specifically designed for automotive use and a correspondingset of protocols and standards. However, additional or alternatewireless communications standards, such as IEEE 802.11 and cellular datacommunication, are also considered within the scope of the presentdisclosure.

In an exemplary embodiment, the ADS 24 is a so-called Level Four orLevel Five automation system. A Level Four system indicates “highautomation”, referring to the driving mode-specific performance by anautomated driving system of all aspects of the dynamic driving task,even if a human driver does not respond appropriately to a request tointervene. A Level Five system indicates “full automation”, referring tothe full-time performance by an automated driving system of all aspectsof the dynamic driving task under all roadway and environmentalconditions that can be managed by a human driver.

Referring now to FIG. 2, an exemplary architecture for an ADS 24′according to the present disclosure is illustrated. The ADS 24′ may beprovided via one or more controllers as illustrated in FIG. 1 anddiscussed in further detail below.

The ADS 24′ includes multiple distinct control systems, as will bediscussed in further detail below. Among the multiple distinct controlsystems is at least one primary control sy stem 30.

The primary control system 30 includes a sensor fusion module 32 fordetermining the presence, location, and path of detected features in thevicinity of the vehicle. The sensor fusion module 32 is configured toreceive inputs from a variety of sensors, such as the sensors 26illustrated in FIG. 1. The sensor fusion module 32 processes andsynthesizes the inputs from the variety of sensors and generates asensor fusion output 34. The sensor fusion output 34 includes variouscalculated parameters including, but not limited to, a location of adetected obstacle relative to the vehicle, a predicted path of thedetected obstacle relative to the vehicle, and a location andorientation of traffic lanes relative to the vehicle.

The primary control system 30 also includes a mapping and localizationmodule 36 for determining the location of the vehicle and route for acurrent drive cycle. The mapping and localization module 36 is alsoconfigured to receive inputs from a variety of sensors, such as thesensors 26 illustrated in FIG. 1. The mapping and localization module 36processes and synthesizes the inputs from the variety of sensors, andgenerates a mapping and localization output 38. The mapping andlocalization output 38 includes various calculated parameters including,but not limited to, a vehicle route for the current drive cycle, and acurrent vehicle location relative to the route. In addition, the mappingand localization module 36 generates a vehicle location output 40. Thevehicle location output 40 includes the current vehicle locationrelative to the route, and is used in a separate calculation as will bediscussed below.

The primary control system 30 additionally includes a path planningmodule 42 for determining a vehicle path to be followed to maintain thevehicle on the desired route while obeying traffic laws and avoiding anydetected obstacles. The path planning module 42 employs a first obstacleavoidance algorithm configured to avoid any detected obstacles in thevicinity of the vehicle, a first lane keeping algorithm configured tomaintain the vehicle in a current traffic lane, and a first routekeeping algorithm configured to maintain the vehicle on the desiredroute. The path planning module 42 is configured to receive the sensorfusion output 34 and the mapping and localization output 38. The pathplanning module 42 processes and synthesizes the sensor fusion output 34and the mapping and localization output 38, and generates a pathplanning output 44. The path planning output 44 includes a commandedvehicle path based on the vehicle route, vehicle location relative tothe route, location and orientation of traffic lanes, and the presenceand path of any detected obstacles.

The primary control system 30 further includes a vehicle control module46 for issuing control commands to vehicle actuators. The vehiclecontrol module employs a first path algorithm for calculating a vehiclepath resulting from a given set of actuator settings. The vehiclecontrol module 46 is configured to receive the path planning output 44.The vehicle control module 46 processes the path planning output 44 andgenerates a vehicle control output 48. The vehicle control output 48includes a set of actuator commands to achieve the commanded path fromthe vehicle control module 46, including but not limited to a steeringcommand, a shift command, a throttle command, and a brake command.

The vehicle control output 48 is communicated to actuators 50. In anexemplary embodiment, the actuators 50 include a steering control, ashifter control, a throttle control, and a brake control. The steeringcontrol may, for example, control a steering system 18 as illustrated inFIG. 1. The shifter control may, for example, control a transmission 14as illustrated in FIG. 1. The throttle control may, for example, controla propulsion system 12 as illustrated in FIG. 1. The brake control may,for example, control wheel brakes 20 as illustrated in FIG. 1.

In addition to the primary control system 30, the ADS 24′ also includesat least one orthogonal co-pilot system 52. The orthogonal co-pilotsystem 52 is configured to verify and, if necessary, override theoperation of the primary control system 30 using distinct algorithmsfrom those employed in the primary control system 30.

The orthogonal co-pilot system 52 includes a path calculation module 54.The path calculation module 54 is configured to receive the vehiclelocation output 40 and the vehicle control output 48. The pathcalculation module 54 processes and synthesizes the vehicle locationoutput 40 and the vehicle control output 48, and generates a pathcalculation output 58. The path calculation output 58 includes a firstpredicted path based on the path planning output 44 and a secondpredicted path based on current actuator settings in the absence of thepath planning output 44. The path calculation module 54 includes avehicle model 56 and employs a second path algorithm, which are distinctfrom the first path algorithm used in the vehicle control module 46.

The orthogonal co-pilot system 52 also includes an obstacle avoidanceverification module 60. The obstacle avoidance verification module 60 isprovided to verify that the vehicle 10 maintains a desired distance fromany detected obstacles, such as other vehicles and/or roadside objects.The obstacle avoidance verification module 60 is configured to receivethe path calculation output 58 and the sensor fusion output 34. Theobstacle avoidance verification module 60 processes and synthesizes thepath calculation output 58 and the sensor fusion output 34 and generatesan obstacle avoidance verification output 62. The obstacle avoidanceverification output 62 may include a Boolean true/false signal or otherappropriate signal indicating the presence or absence of an obstacle inthe first predicted path and/or in the second predicted path. Theobstacle avoidance verification module 60 employs a second obstacleavoidance algorithm, which is distinct from the first obstacle avoidancealgorithm used in the path planning module 42.

The orthogonal co-pilot system 52 additionally includes a lane keepingverification module 64. The lane keeping verification module 64 isprovided to maintain the vehicle in a desired traffic lane. The lanekeeping verification module 64 is configured to receive the pathcalculation output 58 and the sensor fusion output 34. The lane keepingverification module 64 processes and synthesizes the path calculationoutput 58 and the sensor fusion output 34 and generates a lane keepingverification output 66. The lane keeping verification output 66 mayinclude a Boolean true/false signal or other appropriate signalindicating whether the first predicted path and/or the second predictedpath would maintain the vehicle in a current traffic lane. The lanekeeping verification module 64 employs a second lane keeping algorithm,which is distinct from the first lane keeping algorithm used in the pathplanning module 42.

The orthogonal co-pilot system 52 further includes a route keepingverification module 68. The route keeping verification module 68 isprovided to maintain the vehicle on a desired route and within anauthorized operating environment. The route keeping verification module68 is configured to receive the path calculation output 58 and themapping and localization output 38. The route keeping verificationmodule 68 processes and synthesizes the path calculation output 58 andthe mapping and localization output 38 and generates a route keepingverification output 70. The route keeping verification output 70 mayinclude a Boolean true/false signal or other appropriate signalindicating whether the first predicted path and/or the second predictedpath would maintain the vehicle on the route for the current drivecycle. The route keeping verification module 68 employs a second routekeeping algorithm, which is distinct from the first route keepingalgorithm used in the path planning module 42.

The orthogonal co-pilot system 52 further includes an arbitration module72. The arbitration module 72 is configured to receive the obstacleavoidance verification output 62, the lane keeping verification output66, and the route keeping verification output 70. The arbitration moduleprocesses and synthesizes the obstacle avoidance verification output 62,the lane keeping verification output 66, and the route keepingverification output 70, and outputs an orthogonal control output 74. Theorthogonal control output 74 may include a signal to accept the vehiclecontrol output 48, a signal to modify the vehicle control output 48, ora signal to reject the vehicle control output 48.

By providing the orthogonal co-pilot system 52 with algorithms distinctfrom those employed in the primary control system 30, the commanded pathand actuator control signals may be validated independently from anysoftware diagnostic conditions arising in the primary control system 30.

Referring now to FIG. 3, an exemplary architecture for a controller 22′according to the present disclosure is illustrated schematically. Thecontroller 22′ includes at least one primary microprocessor 80 andassociated non-transient data storage provided with a primary controlsystem 30′, which may be configured generally similarly to the primarycontrol system 30 illustrated in FIG. 2. In the exemplary embodiment ofFIG. 3, multiple primary microprocessors 80 are provided, each withassociated non-transient data storage having a primary control system30′. In addition, at least one orthogonal microprocessor 82 is provided,distinct from the one or more primary microprocessors 80. The orthogonalmicroprocessor 82 is provided with associated non-transient data storagehaving an orthogonal co-pilot system 52′, which may be configuredgenerally similarly to the orthogonal co-pilot system 52 illustrated inFIG. 2. Vehicle actuators 50′ are under the collective control of theone or more primary microprocessors 80 and the at least one orthogonalmicroprocessor 82.

By providing the orthogonal co-pilot system 52′ on a distinct hardwarefrom that of the primary control system 30′, the commanded path andactuator control signals may be validated independently from anyhardware diagnostic conditions arising in the one or more primarymicroprocessors 80.

Referring now to FIG. 4, an exemplary embodiment of a lane keepingverification algorithm, e.g. as may be used in the lane keepingverification module 64, is illustrated in flowchart form.

The algorithm begins with an initialization phase 100. Path calculationoutput and sensor fusion output are received, as illustrated at block102. As discussed above, path calculation output includes a firstpredicted path based on the path planning output and a second predictedpath based on current actuator settings in the absence of the pathplanning output, while sensor fusion output may include variouscalculated parameters including, but not limited to, a location of adetected obstacle relative to the vehicle, a predicted path of thedetected obstacle relative to the vehicle, and a location andorientation of traffic lanes relative to the vehicle.

A determination is made of whether the host vehicle is executing a lanechange, as illustrated at operation 104. If the determination ispositive, i.e. the current route does not terminate at the desireddestination, a lane_verify flag is set to ACCEPT, as illustrated atblock 106. Setting the lane_verify flag to ACCEPT indicates that theroute verification algorithm has determined that the predicted pathbased on the path planning output would not result in a deviation from acurrent lane, or that the host vehicle is executing a lane change. Inresponse to the lane_verify flag being set to ACCEPT, the orthogonalcopilot system 52 may command the actuators 50 to accept the vehiclecontrol output 48.

If the determination of operation 104 is negative, control then proceedsto a commanded path evaluation phase 108. In the commanded pathevaluation phase 108, the first predicted path based on the pathplanning output is evaluated to verify that the path planning outputwould not result in the host vehicle deviating from the current lane.

A first time counter t_cp is initialized to zero, as illustrated atblock 110. As will be discussed in further detail below, the first timecounter t_cp corresponds to a temporal window for prediction of vehicleposition along a predicted path based on commanded actuator settings.

A determination is made of whether t_cp is greater than or equal to amaximum evaluation time maxTime, as illustrated at operation 112. Themaximum evaluation time maxTime is a calibratable time periodcorresponding to a desired time window for prediction.

If the determination of operation 112 is negative, i.e. t_cp is lessthan maxTime, then perpendicular distances between the vehicle on thepredicted path and detected lane markers are then calculated, asillustrated in block 116. Here, a perpendicular distance between thevehicle and the lane markers refers to a lateral distance between amidline of the vehicle and detected lane markers.

A determination is made of whether the perpendicular distance calculatedat block 116 is less than an evaluation distance minDist, as illustratedat operation 118. The evaluation distance minDist is a calibratableparameter corresponding to a range of possible vehicle locations at timet_cp, based on a confidence level in the predicted path. In an exemplaryembodiment, minDist is calibrated to increase as t_cp increases, alongwith t_pp discussed below. Thus, for shorter-term predictions a smallerrange is evaluated, while for longer-term predictions a larger range isevaluated.

If the determination of operation 118 is positive, i.e. theperpendicular distance is less than minDist, then t_cp is incremented bya calibratable time increment dt, as illustrated at block 120. Controlthen returns to operation 112.

Returning to operation 112, if the determination of operation 112 ispositive, i.e. t_cp is equal to or greater than maxTime, then thelane_verify flag is set to ACCEPT, as illustrated at block 122. Asdiscussed above, setting the lane_verify flag to ACCEPT indicates thatthe route verification algorithm has determined that the predicted pathbased on the path planning output would not result in a deviation from acurrent lane, or that the host vehicle is executing a lane change. Inresponse to the lane_verify flag being set to ACCEPT, the orthogonalcopilot system 52 may command the actuators 50 to accept the vehiclecontrol output 48.

Returning to operation 118, if the determination of operation 118 isnegative, i.e. the perpendicular distance is equal to or exceeds theevaluation distance minDist, then control proceeds to block 126.

A second time counter t_pp is initialized to zero, as illustrated atblock 126. As will be discussed in further detail below, the second timecounter t_pp corresponds to a temporal window for prediction of vehiclelocations relative to a predicted vehicle path based on current actuatorsettings.

A determination is made of whether t_pp is greater than or equal to themaximum evaluation time maxTime, as illustrated at operation 128. Asdiscussed above, the maximum evaluation time maxTime is a calibratabletime period corresponding to a desired time window for prediction.

If the determination of operation 128 is negative, i.e. t_pp is lessthan maxTime, then perpendicular distances between the vehicle on thepredicted path and the lane markers are then calculated, as illustratedin block 132. As discussed above, the perpendicular distance between thevehicle and the lane markers refers to a lateral distance between amidline of the vehicle and detected lane markers.

A determination is made of whether the perpendicular distance calculatedat block 132 is less than the evaluation distance minDist, asillustrated at operation 134. As discussed above, the evaluationdistance minDist is a calibratable parameter corresponding to a range ofpossible locations, based on a confidence level in the predicted path.As discussed above, in an exemplary embodiment, minDist is calibrated toincrease as t_pp increases.

If the determination of operation 134 is positive, i.e. theperpendicular distance is less than minDist, then t_pp is incremented bythe calibratable time increment dt, as illustrated at block 136. Controlthen returns to operation 128.

Returning to operation 128, if the determination of operation 128 ispositive, i.e. t_pp is greater than or equal to maxTime, then thelane_verify flag is set to LIMIT, as illustrated at block 138. Settingthe lane_verify flag to LIMIT indicates that the lane verificationalgorithm has determined that the predicted path based on currentactuator settings would not result in the vehicle deviating from thecurrent lane within the time interval maxTime. In response to the routeverify flag being set to LIMIT, the orthogonal copilot system 52 maycommand the actuators 50 to modify the vehicle control output 48 tomaintain current actuator settings. In an alternative embodiment, theorthogonal copilot system 52 may command the actuators 50 to modify thevehicle control output 48 to an intermediate value between the currentactuator settings and the vehicle control output 48. In addition, a flagTimeToLaneDev is set to t_cp, as also illustrated at block 138. TheTimeToLaneDev flag indicates a predicted time interval before the hostvehicle deviates from the current lane.

Returning to operation 134, if the determination of operation 134 isnegative, i.e. the perpendicular distance is equal to or greater thanminDist, then the lane_verify flag is set to REJECT, as illustrated atblock 140. Setting the lane_verify flag to REJECT indicates that theroute verification algorithm has determined that both the predicted pathbased on current actuator settings and the predicted path based on thepath planning output would result in the host vehicle deviating from thecurrent lane. In response to the lane_verify flag being set to REJECT,the orthogonal copilot system 52 may command the actuators 50 to rejectthe vehicle control output 48 and to instead perform an alternativemaneuver. The alternative maneuver may include, for example, a fallbackcommand to safely stop the vehicle. Such maneuvers may be referred to asminimal risk condition maneuvers.

As may be seen, embodiments according to the present disclosure mayenable independent validation of autonomous vehicle control commands toaid in diagnosis of software or hardware conditions in the primarycontrol system. Embodiments according to the present disclosure may thusbe more robust, increasing customer satisfaction.

The processes, methods, or algorithms disclosed herein can bedeliverable to/implemented by a processing device, controller, orcomputer, which can include any existing programmable electronic controlunit or dedicated electronic control unit. Similarly, the processes,methods, or algorithms can be stored as data and instructions executableby a controller or computer in many forms including, but not limited to,information permanently stored on non-writable storage media such as ROMdevices and information alterably stored on writeable storage media suchas floppy disks, magnetic tapes, CDs, RAM devices, and other magneticand optical media. The processes, methods, or algorithms can also beimplemented in a software executable object. Alternatively, theprocesses, methods, or algorithms can be embodied in whole or in partusing suitable hardware components, such as Application SpecificIntegrated Circuits (ASICs), Field-Programmable Gate Arrays (FPGAs),state machines, controllers or other hardware components or devices, ora combination of hardware, software and firmware components. Suchexample devices may be on-board as part of a vehicle computing system orbe located off-board and conduct remote communication with devices onone or more vehicles.

As previously described, the features of various embodiments can becombined to form further embodiments of the invention that may not beexplicitly described or illustrated. While various embodiments couldhave been described as providing advantages or being preferred overother embodiments or prior art implementations with respect to one ormore desired characteristics, those of ordinary skill in the artrecognize that one or more features or characteristics can becompromised to achieve desired overall system attributes, which dependon the specific application and implementation. These attributes caninclude, but are not limited to cost, strength, durability, life cyclecost, marketability, appearance, packaging, size, serviceability,weight, manufacturability, ease of assembly, etc. As such, embodimentsdescribed as less desirable than other embodiments or prior artimplementations with respect to one or more characteristics are notoutside the scope of the disclosure and can be desirable for particularapplications.

While exemplary embodiments are described above, it is not intended thatthese embodiments describe all possible forms encompassed by the claims.The words used in the specification are words of description rather thanlimitation, and it is understood that various changes can be madewithout departing from the spirit and scope of the disclosure. Aspreviously described, the features of various embodiments can becombined to form further embodiments of the invention that may not beexplicitly described or illustrated. While various embodiments couldhave been described as providing advantages or being preferred overother embodiments or prior art implementations with respect to one ormore desired characteristics, those of ordinary skill in the artrecognize that one or more features or characteristics can becompromised to achieve desired overall system attributes, which dependon the specific application and implementation. These attributes caninclude, but are not limited to cost, strength, durability, life cyclecost, marketability, appearance, packaging, size, serviceability,weight, manufacturability, ease of assembly, etc. As such, embodimentsdescribed as less desirable than other embodiments or prior artimplementations with respect to one or more characteristics are notoutside the scope of the disclosure and can be desirable for particularapplications.

What is claimed is:
 1. An automotive vehicle comprising: a vehiclesteering system; an actuator configured to control the steering system;a first controller in communication with the actuator, the firstcontroller being programmed with a primary automated driving systemcontrol algorithm and configured to communicate an actuator controlsignal based on the primary automated driving system control algorithm;and a second controller in communication with the actuator and with thefirst controller, the second controller being configured to predict afirst predicted vehicle path based on the actuator control signal and,in response to the first predicted vehicle path deviating from a currentlane, control the actuator to maintain a current actuator setting, andin response to the first predicted vehicle path being within the currentlane, control the actuator according to the actuator control signal. 2.The automotive vehicle of claim 1, wherein the second controller isfurther configured to predict a second predicted vehicle path based onthe current actuator setting and, in response to the second predictedvehicle path deviating from the current lane, control the actuator basedon a fallback command.
 3. The automotive vehicle of claim 2, wherein thesecond controller is configured to predict a first perpendiculardistance between a detected lane marker and the first predicted vehiclepath and to predict a second perpendicular distance between the detectedlane marker and the second predicted vehicle path.
 4. The automotivevehicle of claim 1, wherein the second controller is configured topredict the first vehicle path based on the actuator control signal inresponse to the actuator control signal.
 5. The automotive vehicle ofclaim 1, wherein the first controller is associated with a firstprocessor and the second controller is associated with a secondprocessor.
 6. The automotive vehicle of claim 1, wherein the vehiclefurther includes a second actuator configured to control a vehiclethrottle, a third actuator configured to control vehicle brakes, and afourth actuator configured to control vehicle shifting, and wherein thefirst controller and second controller are additionally in communicationwith the second actuator, third actuator, and fourth actuator.
 7. Amethod of controlling a vehicle, comprising: providing the vehicle withan actuator configured to control vehicle steering, throttle, braking,or shifting; providing the vehicle with a first controller incommunication with the actuator and having a primary automated drivingsystem control algorithm; providing the vehicle with a second controllerin communication with the actuator and the first controller;communicating, from the first controller, an actuator control signalbased on the primary automated driving system control algorithm;predicting, by the second controller, a first predicted vehicle pathbased on the actuator control signal; and in response to the firstpredicted vehicle path deviating from a current lane, controlling theactuator to maintain a current actuator setting.
 8. The method of claim7, further comprising: in response to the first predicted vehicle pathbeing within the current lane, controlling the actuator based on theactuator control signal.
 9. The method of claim 7, further comprising:predicting, by the second controller, a second predicted vehicle pathbased on the current actuator setting; and in response to the secondpredicted vehicle path deviating from the current lane, controlling theactuator based on a fallback command.
 10. The method of claim 9, furthercomprising: predicting, by the second controller, a first perpendiculardistance between a detected lane marker and the first predicted vehiclepath; and predicting, by the second controller, a second perpendiculardistance between the detected lane marker and the second predictedvehicle path.
 11. A system for autonomous control of a vehicle,comprising: an actuator configured to control vehicle steering,throttle, braking, or shifting; a first controller programmed tocommunicate an actuator control signal to the actuator based on aprimary automated driving system control algorithm; and a secondcontroller in communication with the actuator and with the firstcontroller, the second controller being configured to, in response to afirst predicted vehicle path based on the actuator control signaldeviating from a current lane, control the actuator to maintain acurrent actuator setting.
 12. The system of claim 11, wherein the secondcontroller is further configured to, in response to a second predictedvehicle path based on the current actuator setting deviating from thecurrent lane, control the actuator based on a fallback command.
 13. Thesystem of claim 12, wherein the second controller is configured topredict a first perpendicular distance between a detected lane markerand the first predicted vehicle path and to predict a secondperpendicular distance between the detected lane marker and the secondpredicted vehicle path.
 14. The system of claim 11, wherein the secondcontroller is configured to predict the first vehicle path based on theactuator control signal in response to the actuator control signal. 15.The system of claim 11, wherein the first controller is associated witha first processor and the second controller is associated with a secondprocessor.
 16. The system of claim 11, wherein the actuator isconfigured to control vehicle steering, wherein the system furtherincludes a second actuator configured to control a vehicle throttle, athird actuator configured to control vehicle brakes, and a fourthactuator configured to control vehicle shifting, and wherein the firstcontroller and second controller are additionally in communication withthe second actuator, third actuator, and fourth actuator.